Authenticity Assessment of the “Onisiówka” Nalewka Liqueurs Using Two-Dimensional Gas Chromatography and Sensory Evaluation

Recent Developments in Surface-Enhanced Raman Spectroscopy and Its Application in Food Analysis: Alcoholic Beverages as an Example

Surface-enhanced Raman spectroscopy (SERS) is an emerging technology that combines Raman spectroscopy and nanotechnology with great potential. This technology can accurately characterize molecular adsorption behavior and molecular structure. Moreover, it can provide rapid and sensitive detection of molecules and trace substances. In practical application, SERS has the advantages of portability, no need for sample pretreatment, rapid analysis, high sensitivity, and ‘fingerprint’ recognition. Thus, it has great potential in food safety detection. Alcoholic beverages have a long history of production in the world. Currently, a variety of popular products have been developed. With the continuous development of the alcoholic beverage industry, simple, on-site, and sensitive detection methods are necessary. In this paper, the basic principle, development history, and research progress of SERS are summarized. In view of the chemical composition, the beneficial and toxic components of alcoholic beverages and the practical application of SERS in alcoholic beverage analysis are reviewed. The feasibility and future development of SERS are also summarized and prospected. This review provides data and reference for the future development of SERS technology and its application in food analysis.

Characterization of a traditional ripened cheese, Kurdish Kope: Lipolysis, lactate metabolism, the release profile of volatile compounds, and correlations with sensory characteristics

Kope cheese has been characterized based on gross chemical composition, free fatty acids (FFAs), organic acids (OAs), volatile compounds (VCs), and sensory attributes (SAs) during 187 days of the ripening period. C16:0, C18:1cisΔ9, and C14:0 were the most abundant FFAs. Lactic and acetic acids were the most prevalent OAs affecting sensory properties. principal component analysis (PCA) indicated that butanoic acid, butyl hexanoate, and 2,3-butanediol were as key VCs. Protein contents, pH (based on FFA and OA), salt in the moisture (S/M), and water activity (a_w ) (based on VC and SA) were highly correlated with PC2, resulted in two distinct groups. Based on lipolysis and glycolysis studies, early-ripened cheese samples showed lipolysis and lactate metabolism more intensely compared to medium and old-ripened ones. Based on the data of VC and SA, the samples may be classified into three groups: (1) early-ripened cheeses with a salty taste, waxy to cheesy odor, and rubbery texture, (2) medium-ripened cheese with a sweet taste and cheesy odor, and (3) old-ripened cheese with a bitter taste, cheesy to pungent odor, a firm and fragile texture. Textural attributes were highly correlated with proteolysis indices and pH. The results of sensory desirability indicated a significant correlation with pungency, bitterness, and OAs. The cheese samples ripened on the day 127 were selected as the most desirable product. Ripening time had a significant effect on the chemical composition, especially on S/M, pH, and a_w  parameters, which determine the pattern as well as the intensity of biochemical pathways and the final sensory attributes. PRACTICAL APPLICATION: The current study intends to characterize and develop a standardized procedure for producing a traditional cheese called "Kope cheese" by determining the appropriate duration time for the ripening process, determining the main chemical/biochemical compounds that are highly correlated with its unique flavor and texture and distinguishing the key processing factors (such as curd salting, pH values during brining) that have to be altered or controlled carefully during the manufacturing process. The data would help cheese manufacturers determine the optimum time of ripening in order to achieve the best flavor and texture attributes in the final product.

Use of color based chromatographic images obtained from comprehensive two-dimensional gas chromatography in authentication analyses

Comprehensive two-dimensional gas chromatography (GC×GC) has been an important technique used to acquire as much information as possible from a wide variety of samples. Qualitative contour plots analysis provides useful information and in daily use it ends up being handled as images of the volatile organic compounds by analysts. Cachaça samples are used in this paper to showcase the use of two-dimensional chromatographic images as the main source for authentication purposes through one-class classifiers, such as data-driven soft independent modeling of class analogy (DD-SIMCA). The proposed workflow summarizes this fast and easy process, which can be used to certify a specific brand in comparison to other brands, as well as to authenticate if samples have been adulterated. Lower quality cachaças, non-aged cachaças and cachaças aged in different wooden barrels were tested as adulterants. Chromatographic images allowed for the distinction of all brands and nearly every adulteration tested. Sensitivity was estimated at 100% for all models and specificity ranged from 96% to 100%. Different approaches were used, alternating from working with whole-sized images to working with smaller resized versions of those images. Resized chromatographic images could be potentially useful to easily compensate for slight chromatographic misalignments, allowing for faster calculations and the use of simpler software. Reductions to 50% and 25% of the original size were tested and the results did not greatly differ from whole images model. As such, 2D chromatographic images have been found to be an interesting form of evaluating a product's authenticity.

Sensory Characteristics and Volatile Compounds of Herbal Teas and Mixtures of Bush Tea with Other Selected Herbal Teas of South Africa

South Africa has a traditional heritage of using indigenous herbal teas, and the demand for herbal teas motivated by the functional health benefits has far exceeded global supply. This has led to worldwide interest in the sensory characteristics and volatile compound characterisation of herbal drink formulations. The objective of this study was to investigate the descriptive sensory analysis and volatile compounds of bush, special, honeybush and rooibos tea and the blend of bush tea with special, honeybush and rooibos, respectively. The trained sensory panel scored each tea sample for aroma, taste, aftertaste and mouthfeel attributes using sensory evaluation practices. Compound identification was performed by gas chromatography connected to a mass spectrometer (GC-MS). The results of the study demonstrated that rooibos and honeybush tea had an overall sweet-caramel, honey-sweet, perfume floral and woody aroma while bush tea and special tea depicted green-cut grass, dry green herbal and astringent/dry mouth feel. The GC-MS analyses depicted the following compounds 2-furanmethanol, 2-methoxy-4-vinylphenol, D-limonene, dihydroactinidolide, linalool, (E,E)-2,4-heptadienal, and phytol. The blending of bush tea with rooibos and honeybush tea toned down its astringent mouth feel. Compounds identified in this study may be useful markers for potential herbal tea sensory characteristics.

Plants in alcoholic beverages on the Croatian islands, with special reference to rakija travarica

BACKGROUND

This paper aims to record the species used for flavouring and making alcoholic drinks, mainly rakija, on the islands of the Adriatic (Croatia).

METHODS

Our data comes from 295 interviews performed on 36 islands, in both the Dalmatian and Kvarner areas of the Adriatic.

RESULTS

Altogether, 114 species are used-46% from wild locations only, 15% both wild and cultivated, 38% only cultivated and two species are imported. The most common local alcohol is wine, made without spices, but grape pomace distillate is often flavoured with single or mixed species. The mix is called travarica. The most commonly used species are Foeniculum vulgare Mill., Myrtus communis L., Salvia officinalis L., Ruta graveolens L., Juniperus oxycedrus L., Ceratonia siliqua L., Juglans regia L., Citrus spp., Ficus carica L., Laurus nobilis L., Rosmarinus officinalis L., Artemisia absinthium L., Rosa centifolia L., Mentha × piperita L. and M. spicata L. Unfortunately, the widespread phenomenon of distilling Arbutus unedo L. fruits and fermenting Juniperus 'wine' is now extinct. Apart from grapes, the only commonly distilled fruit now is Ficus carica.

CONCLUSIONS

It is striking that nearly all the plants are either wild or cultivated locally, which, in addition to the fact that the alcohol is made locally, shows the incredible local culinary self-sufficiency of the area. The number of species used is also very impressive.